Article of manufacture



Patented Feb. I93? ARTICLE OF MANUFACTURE Willard L. Morgan, Nutley, N. J., assignor to Sylvania Industrial Corporation, Frcdericksburg, Va., a. corporation of Virginia 0 Drawing. Original application July 13, 1935,

Serial No. 31,230. Divided and this application May 2'7, 1936, Serial No. 82,052

9 Claims.

The invention relates in general to flameproof articles, and in particular to such articles formed of organic hydrophilic colloids, as well as to correlated improvements directed towards enhancing the physical characteristics and extending the usefulness of the articles formed from such colloids.

Articles formed from organic hydrophilic colloidal materials, i. e. organic colloids swelling in water such, for example, as sheets and films of regenerated cellulose, are extensively used in the wrapping, packaging, textile and cordage arts, and also in window and stage decoration. These materials are characterized by a flammability at least equal to fibrous paper, which greatly restricts their use in certain installations, especially theatrical stage sets, and window decorations. To render such materials flameproof, the flameproofing agent must have the following requisites:--soluble in colloidal material to such an extent as not to detract from the transparency of the material, and a relatively low vapor pressure. If possible, the flameproofing agent should be further characterized by being non-poisonous,

.non-odorous and light-stable.

It is a general object of the invention to provide fiameproofed articles formed from organic hydrophilic colloidal materials without detracting from the flexibility, transparency and strength of the article.

A more specific object of the invention is to provide a sheet material formed from an organic hydrophilic colloidal material, which is flameproof, transparent and flexible.

Another object of the invention is to provide flameproofed articles formed from organic hyprophilic colloidal materials so that the articles are not only non-flaming, but also non-flame propagating. Furthermore, the invention provides a regenerated cellulose in desired form, sheet or otherwise, which is fiameproofed and does not propagate a flame readily.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises an article of manufacture possessing the features, properties and the relation of elements which willbe exemplified in the article hereinafter described and the scope of the invention will be indicated in the claims.

In accordance with the invention, articles formed from organic hydrophilic colloidal materials may be flameprooied by combining them with a water-soluble salt of a sulphonated, carboxylated or hydroxylated aryl, alkaryl, prefer- (Cl. ice-4o) ably containing a methyl or an ethyl group, or aralkyl derivatives of an acid of phosphorous, such as ortho-phosphoric acid (HaPO4, tribasic) pyrophosphoric acid (H4Pz0'z, tetra basic), metaphosphoric acid (HPOs, monobasic), hypophosphoric acid (HzPOa, monobasic), phosphorous acid (HsPOa, dibasic), hypophosphorous acid (H3PO2, monobasic).

Where the phosphorous acid contains more than one replaceable hydrogen, one or more of such hydrogens may be replaced by an aralkyl group such, for example, as a benzyl radical, by an aryl group, as a phenyl or naphthyl group, or by an alkaryl group, a methyl-phenyl, ethylphenyl, etc. One or more sulphonic, carboxylic or hydroxyl groups may be substituted for the hydrogens of the aromatic rings present in the aralkyl, alkaryl or aryl groups. The watersoluble salts may be formed by replacing, with the ammonium radical or a metal of the alkali or alkaline earth groups, one or more of the hydrogens of the hydroxyl groups attached to the phosphorous atom and/or one or more of the hydrogens of the sulphonic, carboxylic or hydroxyl groups which are attached to the aromatic rings of the aralkyl, alkaryl or aryl groups. The water-soluble salts containing a sulphonic grouping may be considered as having the following probable general formula:

in which P represents an oxygen-containing phosphorous acid residue, R is an aralkyl, alkaryl or aryl group, X is the ammonium radical or a metal selected from the alkali or alkaline earth groups, m is a whole number 1 to 3 and n is a whole number 1 to 4. A general formula for the salts containing the carboxylic and hydroxyl groupings will be as that given above with appropriate substitutions for the sulphonic groupings. It will be understood that wherever this formula is given it encompasses the carboxyl and hydroxyl compounds. When a hydrogen of a phosphorous acid hydroxyl is replaced, the probable general formula would be represented as follows:

in which P represents an oxygen-containing phosphorous acid residue, R is an aralkyl, alkaryl or aryl group, X is the ammonium radical or a metal selected from the alkali or alkaline earth groups, m is a whole number 1 to 3 and n is a whole number 1 to 3.

It has been found that the above mentioned water soluble salts of the sulphonated, carboxylated or hvdromlated aralkyl, alkaryl and aryl phosphorous acids are capable, when used in sufllcient concentration, of rendering organic hydrophilic colloidal materials flameproof. The flameprooflng agents may be used in conjunction with softening agents to maintain the flexibility of the colloid. By way of illustrating the invention, a sheet' of regenerated cellulose is soaked in a soluflon containing 20% of triphenyl phosphate dlsodium sulphonate,

and 15% of glycerine, and the sheet dried. The dried treated sheet is transparent, flexible, strong, and flameproofed to a degree such that the material flames only as long as an external flame is directly applied. When the external flame is removed, however, the flaming of the material ceases after a sort period of time depending upon the concentration of the salt in the material. Compared with ordinary untreated, fibrous paper, the treated material is also relatively non-flame-propagating.

It has now been found that the flameproofness of such articles may be further improved, so that the article does not flame and does not propagate flame, by using a water-soluble salt above described in admixture with a salt of ammonia with an inorganic acid selected from the group consisting of hydrobromic, hydriodic, selenic, sulphuric and phosphoric. For example, a sheet of regenerated cellulose may be soaked in an aqueous solution comprising. 5% by weight of ammonium bromide and 15% by weight of a di-sodium mono-naphthyl phosphate monosodium sulphcnatc.

The treated sheet may be softened, if desired and then dried. When a flame is brought into contact with the treated sheet, the material is destroyed by flameless combustion, but as soon as the flame is removed the combustion stops. The sheet material itself does not propagate the flame, nor does the ash glow for any appreciable time. a

It is to be understood that the flameprooflng agents herein described may be used singly or in compatible admixtures with one another, or combined in any suitable proportion with one or more of the ammonium salts above described. An ammonium salt may be present in the solution in an amount of from 3 to 10%. In general, it has been found sufllcient to incorporate in the material from 10% to 20% by weight of flameprooflng agents herein described, although the upper limit isdetermined by the solubility of the flameprooflng substance in the particular colloidal material treated and the tackiness of finished material, and the lower limit by the flameproofness desired.

The article of the invention may comprise a variety of film-forming, organic, hydrophilic colloids, for example, gelatin, casein, and inflammable cellulose derivatives, such as cellulose ethers. cellulose oxy-ethers and cellulose hydrate. The cellulose hydrate may be regenerated from viscose, cuprammonium cellulose, or

from aqueous solutions of cellulose in inorganic salts, such as zinc chloride: also from the deesterification of cellulose esters, as the acetateslolds.

The flameproofing agents may be added to the original solutions of the colloids from which articles are to be formed, or the article may be impregnated by contacting with an aqueous solution of a flameproofing agent.

The flameprooflng agents impart a high degree of flameproofness to organic hydrophilic colloids without detracting from the transparency, flexibility and strength thereof or of articles formed therefrom. The flameprooflng agents are further characterized by being water soluble, odorless, tasteless and non-poisonous.

Since the water-soluble salts of the aralkyl, alkaryl and aryl phosphorous acids are nonhygroscopicgand have no softening action upon the colloids, they may be used in proportions greater than those possible with flameprooflng agents which are hygroscopic and/or tend to soften such materials. This characteristic also enables a softening agent to be used in conjunction with the flamep'roofing agent to obtain the desired degree of flexibility in the product.

In the appended claims, the expression "flameproof is intended to designate that degree of non-inflammabiiity at which the flameproofed material will not show a self-sustaining combustion when ignited and the external flame removed, and when the ambient atmosphere is at room temperature. Further, the expression "aryl group" is intended to include the aryl, alkaryl and aralkyl group whether containing one or several ring structures of the aromatic series and "sulphonated" encompasses carboxylated and hydroxylated.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

The fireprooflng compositions disclosed herein are claimed in my co-pending application, Serial No. 31,230, filed July 13, 1935 of which the present application is a division.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A flexible transparent article of manufacture, comprising an organic hydrophilic colloid selected from the group consisting of gelatine, casein, cellulose ethers, cellulose oxy-ethers and cellulose hydrate having incorporated therewith a water-soluble salt having the following probable general formula:

ing a transparent sheet or fllm formed of regen-' erated cellulose having incorporated therewith a water-soluble salt having the following probable general formula:

in which P represents an oxygen-containing phosphorous acid residue, R is an aralkyl, alkaryl or aryl group, X is the ammonium radical or a metal selected from the alkali or alkaline earth groups, "m is a whole number 1 to 3, and n" is a whole number 1 to 3, said salt being present in' an amount suflicient to efiect flameproofing of regenerated cellulose.

3. A flexible transparent article of manufacture comprising an organic hydrophilic colloid selected from the group consisting of gelatine, casein, cellulose ether's, cellulose oxy-ethers and cellulose hydrate having incorporated therewith a water-soluble salt of a sulphonated aryl derivative of an acid of phosphorous in an amount-sufficient to efiect flameproofing of said colloid.

4. A flexible transparent article of manufacture comprising a sheet of regenerated cellulose having incorporated therewith from about 10 to about 20% of triphenyl phosphate disodium sulfonate, whereby flameproofing of the regenerated cellulose is efiected.

5. A flexible transparent article of manufacture comprising an inflammable cellulose derivative having incorporated therewith a water soluble salt of a sulphonated aryl derivative of an acid of phosphorous in an amount suflicient to effect flameproofing of said article.

6. A flexible transparent article of manufacture comprising regenerated cellulose having incorporated therewith a water soluble salt of a sulphonated aryl derivative of an acid of phosphorous in an amount suflicient to effect flameproofing of said article.

7. A flexible transparent article of manufacture comprising a sheet or fllm of regenerated cellulose having incorporated therewith from about 10 to about 20% of a water-soluble salt of a sulphonated aryl derivative of an acid of phosphorous.

8. A flexible transparent article of manufacture comprising an organic hydrophilic colloid selected from the group consisting of gelatine, casein, cellulose ethers, cellulose oxy-ethers and cellulose hydrate having incorporated therewith a water-soluble salt of a sulphonated phenyl derivative of an acid of phosphorous in an amount sufl'lcient to efiect flameproofing of said article.

9. A flexible transparent article of manufacture comprising an organic hydrophilic colloid selected from the group consisting of gelatine, casein, cellulose ethers, cellulose oxy-ethers and cellulose hydrate having incorporated therewith a water-soluble salt of a sulphonated aralkyl derivative of an acid of phosphorous in an amount suiiicient to efiect flameproofing of said article.

WILLARD L. MORGAN. 

